Surfactant based extraction for recovering enzymes is a field of active research both in academia and industry.
Phase separation using non-ionic surfactants but high amounts of salts (2 to 30% w/v) is claimed in, e.g., U.S. Pat. No. 6,105,786. Although salts are inexpensive, these processes may not be commercially attractive for large scale recovery of commodity products, primarily because of the huge environmental load such high amounts of salt would impose. Furthermore, corrosion could potentially be an issue needing an expensive material of construction.
An alternative is to induce phase separation using temperature. Traditional cloud point extraction (heating above the cloud point of non-ionic detergent with or without the aid of the centrifuge) do not work well for extracting proteins directly from fermentation broth containing high starting protein concentrations (typically obtained in industrial fermentations for commodity products). This is because of phase separation/disengagement problems due to high viscosity and low density difference of phases.
A new extraction process based on non-ionic surfactants has been developed and is described herein that is useful for recovering proteins in high yields directly from fermentation broth in a single step.